The present invention relates in general to noise reduction and more particularly concerns novel apparatus and techniques for enclosing a nosiy machine to improve the noise environment while allowing workers to observe operation of the machine. The invention not only reduces sound but is also useful in helping keep parts clean and improving the lighting of the machine while being relatively inexpensive to fabricate. The invention also provides relatively easy and quick access to the machine enclosed.
The specific embodiment of the invention is especially useful in connection with vibratory feeder bowls. Of the estimated at least 500,000 vibratory feeder bowls in use in the United States, more than half produce noise in excess of 90dB.sub.A for 8 hours in the mode in which they are used, exceeding OSHA acceptable limits. One prior art approach for reducing the noise was to use plastic linings which wore out or different metals on the bowls. Nevertheless, the parts still impact against each other to produce excess noise. Still another source of noise is the magnetic vibrating mechanism under the bowl.
It is an important object of this invention to reduce the noise environment around machines.
It is a further object of the invention to achieve the preceding object while allowing relatively easy access to the machine during operation or assembly.
It is a further object of the invention to achieve one or more of the preceding objects while facilitating observation of the machine operation by the worker.
It is still another object of the invention to achieve one or more of the preceding objects in a manner that admits parts to the machine.
It is a further object of the invention to achieve one or more of the preceding objects with apparatus that is relatively easy and inexpensive to manufacture, install and remove when access to the machine is desired.
It is another object of the invention to achieve one or more of the preceding objects in connection with vibratory feeder bowls.